1. Field of the Invention
The present invention relates, in general, to a vibration damping device, which is interposed between parts to be connected to each other to make a vibration damping state, thus connecting the parts to each other in the vibration damping state and, more particularly, to a fluid-filled type vibration damping device, which executes a vibration damping function using vibration damping effects realized by flowing actions of a fluid charged in the device. In more detail, the present invention relates to a fluid-filled type vibration damping device, which is configured to switch a fluid passage communicating a pressure-receiving chamber, charged with a fluid and an equilibrium chamber between an opened state and a closed state.
2. Description of the Related Art
As an example of a conventional fluid-filled type vibration damping device, JP-A-2004-150546 (Patent document 1) discloses a fluid-filled type vibration damping device, which is configured to switch a fluid passage communicating a pressure-receiving chamber with an equilibrium chamber between an opened state and a closed state by actuating a movable valve body using pneumatic pressure or electromagnetic force, thus controlling the vibration damping performance thereof. The movable valve body can be actuated by the action of a magnetic field formed by a solenoid coil.                [Patent Document 1] JP-A-2004-150546        
In this case, to maintain the movable valve body in either of the two states, it is necessary to supply a continuous application of electricity to the solenoid coil. However, to supply the continuous application of electricity to the solenoid coil, electric power consumption of the solenoid coil is increased and, at the same time, heat produced from the solenoid coil is increased, so that durability of the solenoid coil may be reduced.